The present invention relates generally to a bar code reading apparatus, and more particularly to a non-decoded bar code reading apparatus arranged so as to output bar code data to an external bar code-to-character code converter (or decoder) without converting or decoding it into character code data (ASCII, JIS or others).
Conventionally, an apparatus known for reading optical information is a decoded type bar code reading apparatus, in which bar code data is read through a scanner to be decoded by an decoder and then encoded into the corresponding character data which is in turn outputted to an external circuit. There is a problem which arises with such an arrangement of the conventional bar code reading apparatus, however, in that in addition to the scanner, the decoder is encased in the apparatus. This limits the optically readable bar code to a bar code of the type suitable for the decoding and encoding programs in advance incorporated into the decoder. On the other hand, a non-decoded type bar code reading apparatus is also known which is not equipped with a decoder, the bar code data read by the scanner being directly output to an external decoder after being electrically processed. According to such a non-decoded type bar code reading apparatus, the scanner and the decoder are not integrated so as to allow use with a combination of different systems. One of the important problems faced in such a conventional non-decoded type bar code reading apparatus relates to the fact that the reading accuracy or capacity allowed for the whole system greatly depends upon the decoding ability of the decoder. In addition, because the conventional non-decoded type bar code reading apparatus directly outputs the bar code information to an external circuit after performing only the electrical process, there is the possibility that the output signal thereof does not correspond to the read bar code due to generation of optical and electrical distortion in the optically reading operation. Also, it is difficult to accurately decode the bar code data because of scattering in the dimensions of printed bars and spaces (separation between the successive bars) of the bar code.